问Rails j查询section_tag当前值未重置为缺省值

EN

class CreateCartItems < ActiveRecord::Migration[5.2]
  def change
    create_table :cart_items do |t|
      t.references :cart, index: true, foreign_key: true
      t.references :train_class, index: true, foreign_key: true
      t.references :passenger, index: true, foreign_key: true

      t.integer :passenger_qty
      t.integer :male
      t.integer :female
      t.decimal :unit_price
      t.decimal :total_price
      t.string  :outbound

      t.timestamps
    end
  end

<div class="female-male-options">
     <div class="female-box">
       <%= f.label (t "reservations.female_passengers"), {:class => 'form-container-item-label'} %>
       <%= f.select(:female, @travelers, {selected: @travelers_select}, { id: 'female'}) %>
      </div>
      <div class="male-box">
          <%= f.label (t "reservations.male_passengers"), {:class => 'form-container-item-label'} %>
           <%= f.select(:male, @travelers, {selected: @travelers_select}, { id: 'male'}) %>
       </div>
  </div>

class ReservationsController < ApplicationController
  def show
    ...
    @travelers = [0,1,2,3,4,5,6,7,8,9,10]
    @travelers_select = params[:travelers]
  end
end